"If you were running for president instead of your brother, I would vote for you, because from the point of view of depth, intuition and education, for you, it seems, everything has passed to the female side [of the family]" Mikhalkov said, RIA-Novosti reported.
The two debaters in Monday's event were acting as representatives of the presidential candidates. Putin has said he will not take part in debates personally since they would require him to officially take time off from his job as prime minister.
Prokhorova dominated much of the debate, noting the lack of cultural development in Russia and chiding the current leadership for their lack of attention to this area. She positioned her brother as the only candidate who places culture and education at the head of his program.
Mikhalkov quoted Pushkin and criticized Prokhorov for his wealth and lack of family, arguing that Prokhorov would be a bad choice to lead people with whom he has little in common.
Prokhorov has said he has not yet decided whether he will take part in presidential debates with Putin proxies.
Some media outlets and bloggers have criticized the debates as absurd. "Pre-election debates in Russia are held without the participation of the candidates," Delovoi Petersburg wrote.
Blogger Oleg Severyukhin wrote that "the debates of the candidates' representatives are a parody of presidential elections in Russia."
"Everything will be like in Turkmenistan," he said, referring to Sunday's election in which President Gurbanguly Berdymukhammedov was reelected with 97 percent of the vote.